Thread-controlling mechanism for sewing-machines.



No. 805,870. PATENTED NOV. 28, 1905. D. MILLS.

v THREAD GONTROLLING MBCHANISM FOR SEWING MACHINES.

APPLICATION FILED NOV. 9. 1897.

3 SHEETS-SHEET 1.

w|TNEssEs=- 21" INVENTOR t1-1:32. Q ,i ,i @fe/Jr." I L'. M

No. 805,870. PATENTED NOV. 28, 1905.

D. MILLS. THREAD GONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED NOV. 9. 1897.

' XG 3 SHEETS-SHEET 2.

No. 805,870. PATEN'I'ED NOV. 28, 1905. D. MILLS. THREAD GONTROLLING MEGHANISM FOR SEWING MACHINES APPLICATION FILED NOV. 9. 1897.

3 SHEETS-SHEET 3.

WITNESSES:

f Wag/y @um INVENTOR LM-X' W Lvl.. ATTORNEY NITED STATES PATENT OFFICE.

DANIEL MILLS, OF PHILADELPHIA STANDARD SEWING MACHINE CORPORATION OF OHIO.

PENNSYLVANIA, ASSIGNOR TO THE lCOMPANY, OF CLEVELAND, OHIO, A

g No. 805,870.

Specification of Letters Patent.

Patented NOV. 28, 1905.

Application filed November 9, 1897. Serial No. 657.909.

To all whom, 2S may concern.-

Be it known that I, DANIEL MILLS, acitizen of the United States, and a resident of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Thread-Pull-Ofi'l Mechanism for Sewing-Machines, of which the following description, taken in connection with the drawings herewith accompanying, is a specification.

This invention relates to that class of sewing-machines employing a shuttle or looper for carrying the needle-thread loop around a bobbin to interlock with the under or bobbin thread and form a lock-stitch.

As well understood by those skilled in the art, it is desirable that some means be provided in machines of this class topull ofi a suiiicient amount of thread from the bobbin as may be required for each stitch and present the same in a slack condition to the upper thread, whereby it may be taken up by the latter without undue strain thereon in completing the stitch. I am aware that different forms of devices or pull-offs have been employed for thus acting upon the under thread, one form of which, as embodied in another application of mine now pending, (bearing Serial No. 613,325,) consists of a reciprocating bar operating across the path of the needle and having an opening therein through which the bobbin-thread passes to be acted upon by the pull-o1 and drawn from the bobbin; but in this form of device the needle operates through the opening therein, and the slack upper thread is also acted upon by the pulloff when operating to draw the under thread from the bobbin. These features have been found to be undesirable in some instances; and it has been one of the objects of my present invention to avoid the same by providing a pull-off for acting upon the under thread to draw off the required amount for the stitch that will operate in a path at one side the vertical path of the needle and without acting upon the needle-thread. I/Vhen the pulloff thus acts upon the under thread to draw oi the same from the bobbin at every stitch, the purl formed by the interlocking of the upper and under threads in making buttonholes is located at a point back from the edge of the buttonhole. It isdesirable, however, in certain cases to have the purl at the inside edge of the buttonhole, and having this in mind it has been a further object of my present invention to provide the machine with means for operating the pull-off in a manner Awhereby it will so act upon the under thread as to draw the same from the bobbin at such time and in such quantity as to cause the purl to be formed at the inner edge of the buttonhole. This object I accomplish by means of suitable mechanism for operating the pull-off to act upon the under thread only at every alternate or other predetermined stitch.

Referring to the drawings, Figure l represents a plan view of the cloth-plate of a buttonhole-sewing machine, partly broken away, showing a construction embodying my invention. Fig. 2 represents a side or edge view of a portion of the same, showing the connection between the pull-oit' and the buttonhole-clampoperating mechanism. Fig. 3 is a cross-section through line 3 3 of Fig. 2 looking in the direction indicated by the arrow. Figs. 4:, 5, and 6 are front end Views of a portion of the machine in dotted lines, showing the pull-off in full lines and its action at different times during the formation of a stitch. Figs. 7 and 8 are views of a piece of goods containing a buttonhole, taken in cross-section through the latter, showing the formation of the stitches as produced by my improved pull-off.

To explain in detail, a represents a portion of the bed-plate of a sewing-machine; c', a rotating shuttle supported within a racewayframe 02, located in a hanger a3 on the under side of the bed-plate; a driving-shaftarranged beneath the bed-plate for operating the shuttle a', and 6 my improved thread-pulloli. This pull-oft' consists of an arm or lever carried at one end of an operating rockshaft Z2 and being arranged to operate in a vertical plane just forward of the vertical path of the needle a, as will be understood from the relative positions of the parts as shown in Figs. l and 2. The rock-shaft b, which carries the pull-ott, is supported in bearings in the hangers e3 and a5 on the under side of the bed-plate and is provided with an arm Z22, having a pin or roller b3.tliereon, adjacent to its outer end, which is adapted to be engaged by a cam or eccentric on the shaft ai. This arm b2 is movably heldin a normal stationary position to hold the pull-offin its normal position by means of a spring which is connected at one end with the bed-plate and IOO at its opposite end with the said arm to hold the latter with an adjusting-screw l2 therein in contact with one edge of the hanger a5. The arm b2 is thus held in anormal stationary position during a part of the revolution of the cam b4 and until the latter reaches a position to engage with the roller thereon, at which time said cam moves the arm b2 against the pressure of the spring b5, an'd thereby rocks the shaft to operate the connected pull-off After the arm Z22 has thus been operated or moved forward and the cam b4 continues its revolution said arm with the connected pullof b are returned to their normal position, with the adjusting-screw b in -contact with the hanger, under the action of the spring b5.

The action of the pull-ofi upon the thread when operated by the means described is as i follows: The pull-off remains stationary in its normal inoperative position, as shown in Fig. 4, during the descent of the needle and until after it has raised above the shuttle and the latter has entered the loop 1 thrown out by said needle, at which time and while the shuttle is carrying the loop around the bobbin the pull-off moves forward to engage the under thread 2 and pull or draw otl' a sufficient quantity of the same from the bobbin as may be required for the next stitch, as shown in Fig. 5, after which it moves back to its normal position away from contact with the thread and also from the path of any of the moving parts of the machine to leave said thread in a slack condition, as shown in Fig. 6, to be drawn up through the goods by the upper thread without undue strain on the same, as will be understood.

The movement of the pull-off may be regulated to draw off more or less thread from the bobbin, according to the thickness of the material being operated upon or the character of the work being performed, by turning the Y screw 56 in the rock-shaft arm b2, so as to adjust the position of the roller 3 either toward or away from the shaft ai, whereby the said arm b2 and the connected pulloff will be moved a greater or less distance by the cam b".

The machine to which my improved pullofl is applied, as herein shown, is a buttonhole-sewingmachine. In buttonholing when the pull-off acts upon the under thread to pull off the same quantity from the .bobbin for each stitch the under thread is drawn by the upper thread above the goods at the inner edge of the buttonhole, as at 3 in Fig. 8, and at the next stitch at the outer edge of the row of stitching, forming the sides of the buttonhole, the under thread is again drawn by the upper thread above the goods, as at I in Fig. 8, and as each stitch is tightened by the action of the take-up the points of interlocking between the upper and lower threads of each stitch are brought to a position in line with each other, and so form the purl of the buttonhole, as at 5 in Fig. 8. By reason o f an equal length of slack under thread being thus taken from the bobbin for each stitch the purl formed by the interlocking between the upper and under threads will necessarily be between the opposite sides of the row of stitching or back from the inner edge of the buttonhole, as shown.

As hereinbefore stated, it is desirable in certain instances to have buttonholes stitched with the purl at the inner edge of the same. To accomplish this, I have provided means for operating the pull-off so that it will act upon the under thread to draw the same from the bobbin only at every alternate stitch. The result secured by such action of the pull-oft1 in the formation of the buttonhole stitch is as follows: The tension upon the under thread being quite strong, so that the thread draws tightly between the bobbin and the work, as shown in Fig. 4, when the needle descends at the inner edge of the buttonhole and the shuttle takes the thread-loop from the same tointerlock with the bobbin-thread in the usual manner the pull-off does not act upon the thread, so that as the stitch is tightened the under thread by reason of its being so tautis only drawn by the upper thread to a point at the face sideof the goods and at the inner edge of the buttonhole, as at 6 in Fig. 7. Now as the needle descends through the goods at the outer edge of the row of stitching and the thread-loop is taken therefrom to interlock with the under thread the pull-ofil acts upon the latter in the manner as hereinbefore set forth and draws a sufficient quantity of the same from the bobbin, so that when such under thread is drawn up by the upper thread through the goods there will be a suflicient quantity of the same, as shown at 7 in Fig. 7, to be drawn over-to the inner edge of the buttonhole and in line'with the purl 6 as the next stitch is made. In this manner, the pull-off being inoperative when the stitch is taken at the inner edge of the buttonhole and coming into operation to draw the thread from the bobbin in the proper quantity as the stitch is takenat the outer edge of the row of buttonhole stitching, it will be understood that the purl formed by the interlocking of the stitches will necessarily b'e at the inner edge of the buttonhole, as described.

The pull-od I) may be operated to act upon the under thread at every alternate stitch, as described, by any suitable means, the 'means as herein shown being as follows: The rockshaft Z1', which carries the pull-off, is supported to slide longitudinally in its bearings and is connected at its inner end, through the medium of a link bs, with one arm CZ of an elbowlever d, which latter is pivotally supported on a stud d2 on the under side of the bedplate, as shown in Figs. l and 2. The other arm Zof said elbow-lever is provided with an angular or cam slot (Z4, into which a pin or projection c3, carried by a vibrating lever c,

IOO

IOS

IIO

IIS

extends and operates to actuate the elbow-le- VGI.

The buttonhole-machine to which my invention is applied, as herein shown, is the same as that which is more fully described and illustrated in other applications of mine now pending, bearing Serial Nos. 611,485 and 611,486, and the lever c is the same in arrangement and operation as the like lettered part in said pending applications. This lever c, which is an elbow-lever, is pivotally supported on the bed-plate at c and is adapted to be operated at one end from the drivingshaft of the machine through the medium of any suitable mechanism (a simple means being like that shown in said pending applica# tions) and its opposite arm c2 being connected with the work-holder to vibrate the same. The position of the lever c while being operated is adjusted so as to shift the work-clamp, whereby it will present one side of the louttonhole to be stitched, and after such side has been completed present the opposite side for stitching by means of the rotating formercam c4 and the yoke f, the latter being secured at one end to the lever Gand having two stop-lingers f2 f2 thereon for engaging with the opposite sides of the former-cam to regulate the throw and position of the lever c, as more fully set forth in my said pending application bearing Serial No. 611,485.

ln operation as the lever c is vibrated to move the work-holder back and forth while one edge of the buttonhole is being stitched the pin c3 thereon is caused to move back and forth in one end 8 of the cam-slot d* in the elbow-lever CZ and move or operate the latter so as to communicate a vibrating movement to the end of its arm d. Such movement of the elbow-lever d/ moves the rock-shaft 5 longitudinally in its bearings and shifts the pullofl' thereon back and forth from an operative position for engaging with the under thread when actuated by the cam b4, as shown by dotted lines in Figs. 1 and 2, to an inoperative position, where it will not engage with the under thread when moved forward, as shown by full lines in said Figs. 1 and 2. It will of course be understood that the timing of the movement given to the pull-off from the elbow-lever CZ as just described is such that it will act upon the thread to draw the same from the bobbin as the stitch is taken at the outer edge of the buttonhole stitching and skip the same as the stitch is taken at the inner edge of the buttonhole, in the manner herein before described. As the lever c is shifted, through the action of the former cam after one edge of the buttonhole is stitched, so as to change the position of the connected work-holder to bring the opposite edge of the buttonhole into position to be stitched, the pin c3 thereon is at the same time moved to the opposite end 9 of the camslot in the elbow-lever cZ, in which end it operates to move the pull-o to and from an operative position at every alternate stitch in the same manner as before described. As the pin c3 is thus moved at the shifting of the workholder from one end 8 of the cam-slot to the other end 9 it moves the lever CZ, and thereby changes the position of the connected pull-off, whereby the time of action of the latter will be changed in order that it may actupon the thread when such opposite edge of the buttonhole is being stitched in the same manner as before described relative to the first edgekz'. c.

to act upon the thread when the stitch is taken at the outer edge of the row of stitching and skip the same as the stitch is taken at the inner edge.

The longitudinal movement given to the rock-shaft, with its connected parts, as described, does not in any Way interfere with the rocking movement communicated to the same from the cam bi, for the reason that the longitudinal movement is but very little and the pin or roller 3 always remains in a position to be acted upon by the said cam bf. When it is desired, however, to employ the pull-off for acting upon the thread at every stitch, the link bs is disconnected from the shaft b', and the pull-off lever 6 and arm b2 on the latter are adjusted longitudinally thereon, so as to contact with the adjacent sides of the hangers a3 and a5, and thus be held with the shaft from longitudinal movement.

Having thus set forth a practical embodiment of my invention, it will be understood that the same may be more or less materially modified without departure from the spirit of my invention, for what I claim isl. In a -sewing-machine, the combination with the stitch -forming mechanism, of a thread-pull-off, and means for operating said pull-ofil to act upon the thread only at each alternate stitch.

2. In a sewing-machine, the combination with the stitch-forming mechanism, of a bobbin-thread pull-oif, and means for operating said pull-off to act upon the bobbin-thread only at each alternate stitch.

3. In a sewing-machine, the combination with the stitch -forming mechanism, of a thread-pull-off operative in a path at one side of the path of the needle, and means for operating said pull-off to act upon the thread only at each alternate stitch.

4. In a sewing-machine, the combination with the stitch forming mechanism, of a thread-pull-oft', means for operating said pulloff to act upon the thread only at each alternate stitch, and adjusting means for regulating' the action of the pull-off.

5. In a sewing-machine, the combination with the stitch -forming mechanism, of a thread-pull-off, and means for operating said pull-off to act upon the thread during the formation of certain predetermined stitches and IOO IIO

to maintain said pull-off in inoperative position relative to said thread during the formation of certain other predetermined stitches.

6. In a sewing-machine, the combination with the stitch-forming mechanism, of a bobbin-thread pull-off, and means for operating said pull-off to act upon the bobbin-thread during the formation of certain predetermined stitches and to maintain said pull-off in inoperative position relative to said bobbinthread during the formation of certain other predetermined stitches.

7. In a sewing-machine, the combination with the stitch forming mechanism, of a thread-pull-off, a slidably-mounted rock-shaft carrying said pull-off, means for rocking said shaft to cause the pull-ofil to act upon the thread, and means for moving said shaft longitudinally to 'shift the pull-oif to and from its operative path of movement for acting on the thread.

8. In a sewing-machine, the combination withthe stitch -forming mechanism, of a thread-pull-off, means for operating said pulloff to act upon the thread, a slidably-mounted shaft carrying said pull-off, a lever having connection with said shaft and provided with a` cam, and a second lever engaging with the said cam of the first-mentioned lever and operating the Ilatter to communicate a reciprocating movement to the pull-off-carrying shaft, for the purpose set forth.

9. In a sewing-machine, the combination with the stitch forming mechanism, of a thread-pull-oif, means for operating said pullof to act upon the thread, a slidably-mounted shaft carrying said pull-0E, a pivoted elbowlever having one arm connected with said shaft and its other arm provided with a camslot, and a lever having means extending and operating within said cam-slot in the elbowlever to operate the latter and communicate a longitudinal movement to the pull-oif-carrying shaft, for the purpose set forth.

10. In a buttonhole-sewing machine, the combination with the work-holder-operating mechanism, of a thread-pull-oif, means for operating said pull-off to act upon the thread, and means forming an operative connection between said pull-off and the work-holderoperating mechanism whereby the pull-off is operated by the latter to alternately assume an operative and inoperative position for acting upon the thread.

11. In a buttonhole-sewing machine, the combination with the work-holder-operating mechanism embodying a vibrating lever, of a thread-pull-oif, means for operating said pullofi' to act upon the thread, and means forming an operative connection between said Vibrating lever and the pull-off whereby the latter is moved by said lever to and from its operative path of movement at certain predetermined stitches.

12. In a buttonhole sewing machine, the

combination with the stitching mechanism, and the work-holder-operating mechanism yfor presenting first one side of a buttonhole and then the other to said stitching Imechanism, of a thread-pull-o, means for operating said pull-off to act upon the thread, and means for changing the time of action of the pulloif upon the shifting of the work-holder for presenting the opposite sides of the buttonhole to the stitching mechanism.

13. In a buttonhole-sewing machine, the combination with the stitching mechanism, and the work-holder-operating mechanism for presenting first one side of a buttonhole and then the other to said stitching mechanism, of a thread-pull-oif, means for operating said pulloif to act upon the thread only at each alternate stitch, and means for changing the time of action of the pull-off upon the shifting of the work-holder for presenting the opposite sides of the buttonhole to the stitching mechanism.

111. In a buttonhole-sewing machine, the combination with the stitching mechanism,and the work-holder-operating mechanism for presenting first one side of a buttonhole and then the other to said stitching mechanism, of a thread-pull-oif, means for operating said pulloH to act upon the thread during the formation of certain predetermined stitches and to remain inoperative during the formation of certain other predetermined stitches, and means for changing the time of action of the pull-off upon the shifting of the work-holder for presenting the opposite sides of the buttonhole to the stitching mechanism.

15. In a buttonhole-sewing machine, the combination with the stitching mechanism,and the work-holder-operating mechanism for presenting lirst one side of a buttonhole and then the other to said stitching mechanism, of a th read-pull-off, means for operating said pulloff to act upon the thread during the formation of certain predetermined stitches and to remain inoperative during the formation of certain other predetermined stitches, and means forming an operative connection between the work-holder-operating mechanism and the pull-off whereby the time of action of the latter will be automatically changed upon the shifting of the'work-holder for presenting the opposite sides of the buttonhole to the stitching mechanism.

16. In a sewing-machine, the combination with the stitch-forming mechanism, of a rockshaft provided with a pull-off arm, means for movably holding the rock-shaft with its said pull-off in an adjustable stationary position, and means for operating the rock-sh aft to cause the pull-off to act upon the bobbin-thread.

17. In a sewing-machine, the combination with the stitch-forming mechanism, of a rockshaft provided with a pull-off arm and with a second operating-arm, said operating-arm being provided with an adjusting-screw for en- IOO IIO

gagement with a stationary part of the machine, a spring for movably holding said operating-arm in a normal stationary position with its screw in contact with said stationary part, and a driving-shaft having a cam or eccentric thereon for operating said rock-shaft `and connected pull-off.

and means for reversing the action of said pulloff for overseaming the respective sides of the buttonhole.

19. In a buttonhole-sewing machine, using an upper and an under thread, a throat-plate, and means for feeding the material, in combination with stitch-forming mechanism including a bobbin,'and a thread-pull-of operatively mounted beneath the throat-plate and adapted to engage the under thread on its Way from the bobbin to the material, and means for actuating said pull-oli:1 whereby a predetermined quantity of under thread is drawn from the bobbin at alternate stitches only.

DANL. MILLS. Witnesses:

CHAS. F. DANE, FRED W. DANE. 

